code: def on_preprocess_end(self, positions):
      self.on_preprocess_end_called_count += 1
  
file_path: cugraph/python/cugraph/cugraph/tests/layout/test_force_atlas2.py
imports: import time
  import pytest
  import cugraph
  from cugraph.structure import number_map
  from cugraph.internals import GraphBasedDimRedCallback
  from sklearn.manifold import trustworthiness
  import scipy.io
  from cugraph.datasets import karate, polbooks, dolphins, netscience, dining_prefs
label_desc: Use image node_id 2 for calling the TestCallback obj's underlying member method code with example usage: obj.on_preprocess_end(positions) without return types